To muffle the operating sound, it is known to cover machines completely against the ambient air space by means of a sound-suppressing cover. However, such a cover cannot always be configured so as to cover the entire machine set, because in most cases there is the necessity to lead the machine shaft to the outside so that an opening for the shaft lead-through must be provided in the cover. The gap then appearing between the shaft and the shaft lead-through in the cover must be relatively large because the spring-mounting of the cover, insulated against structure-borne noise, will cause relative motions between the shaft and the cover to occur, which may also include unavoidable resonant vibrations. But gap-like openings largely nullify the sound-reducing effect of the cover.
Therefore, the German Pat. No. 1,181,010 describes an arrangement in which the cover, installed so as to be insulated against structure-borne sound, is assembled to the bearing housing at the point where the shaft passes therethrough with an elastic seal which makes contact all around and insulates against structure-borne sound. Thus, the bearing housing itself forms a part of the cover which includes the shaft lead-through, and is taken out of the structure-borne sound insulation. In this known arrangement, the external form of the bearing housing is made as smooth as possible so that the cutout required to assemble the cover will be of the simplest possible shape, nor must there be inside the bearing housing a path for the sound to run parallel to the shaft. Accordingly, the known arrangement requires a specific constructional adaptation of the bearing and the bearing housing even when it is applied as a shaft lead-through, which shaft lead-through is not insulated against structure-borne sound, of a cover installed so as to be insulated against structure-borne sound. Moreover, there is the danger that because of the presence of lubricating oil in the bearing, oil drops or oil mist will enter the interior of the cover wherein an underpressure usually prevails causing undesirable contamination there.
Accordingly, it is an object of the invention to provide a sealing arrangement for a machine equipped with a cover and a bearing outside of the cover, the cover having a shaft lead-through and being installed so as to be insulated against structure-borne sound. More specifically, it is an object of the invention to provide such a sealing arrangement between the cover and bearing which is easily produced and which prevents the emission of sound from the interior of the cover and which prevents oil or oil mist being drawn from the bearing.